At 11.21 2012.02.28, you wrote:
>> > Seems like you could do a rocket motor ignitor with them pretty=20
>nicely.  :) The
>> > reverse voltage thing is obvious, but they also fail spectacularly=20
>with high inrush
>> > currents.
>
>Best Tantalum failure I've seen was in a working PCB. It shrieked then
>warbled, then smoked, then burst into flame with a nice flame jet, all
>the while still supplying sound effects (as I recall) and then
>literally exploded with a very impressive bang for an indoor event.

I too once assisted to a tantalum "live" event.. really impressive, what
remained was a hole in the multilayer PCB that made the whole board crap
(even although I'm used to desperate "100 little wires" repairs..). There
was no voltage spike or whatsoever, it was battery operated, I still don't
know why it happened after hundreds hours of honourable service.

I then had another tantalum failure which caused no damage to the PCB but
big damage in other ways, as it was a data logger on a critical mission
which was severely current limited but with the shorted tantalum the logger
stopped working anyway.

Never ever wanted to use tantalum caps since then, although I reckon that
there are still cases where they may be required (I'm a happy user of 10uF
0603 ceramic caps now, but when you need 100uF, they start to be really
expensive).

As I understand it, though, what really takes fire is not tantalum, but
manganese contained in the standard ones. There are tantalum caps which
are absolutely safe in the fire department regard. There remain a last
but not least problem, i.e. wars and murder done to control the mining
of this precious element, however I know that some manufacturers do
guarantee and certify that the tantalum they use is not made from blood.

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.